Object renders black with UV mapped image?
I've had this problem in the past when using glossy, glass or transparent materials with an alpha.

Here is the correct setup for alpha textures with a glossy (same process for glass and transparent).

You can remove the transparent node if you don't need it.

The Curve node is there in case the black or the white are a little bit grey in the alpha.

NB there is an invert node for when I use inverted alphas. Not useful here.